Various types of electronic flash units or flash guns are known utilizing an elongated flash tube which is associated with a reflector of generally parabolic shape. A flash gun in which the reflector can be pivoted about the axis of the elongated tube permits direct, indirect, or, if the reflector is sectioned, mixed direct-indirect illumination. Structures in which the reflector is fixed in a housing, and the entire housing is pivotable with respect to a holder adapted for attachment to a camera, for example a flash shoe, are well known; in other structures, however, the housing is stationary, and the reflector is pivotable within the housing. It has been proposed to position the elongated light source and a section reflector in a cylindrical housing which is closed off at the front by a light transmissive disk, for example a plastic disk. The cylindrical housing is joined to a housing of essentially similar longitudinal extent which retains the operating circuitry, batteries, or other electrical devices to supply energy to the flash tube and to meter the amount of light emitted therefrom. The housing portion itself carries the attachment shoe. The known flash gun can be used for selectively different illumination of an object by suitable direction of the reflector so that the subject to be illuminated is either directly illuminated, or indirect illumination is directed to a ceiling or other reflective screen; sectional reflectors permit, selectively, mixed direct and indirect illumination. In use, the apparatus is coupled to the camera by engaging the flash shoe on the housing of the flash gun with the matching camera shoe. The illumination of the subject to be photographed thus is approximately the same as the viewing direction from the camera, since the electronic flash gun and its light source--reflector combination is attached to the camera. For many photographs, this is a suitable illumination; frequently, however, it is desired to have the light emanate from a location other than the position of the camera, or to use a further flash gun which is termed a "slave" unit either for fill-in or highlight or general illumination.